I wouldn't worry about the TTSX pencilling thru. They have a much larger hollow cavity than the original TSX bullet that is intended to initiate expansion earlier. I am a HUGE proponent of the TSX and TTSX bullets. I currently shoot them in my wifes 270 winchester 130gr TTSX and have complete confidence on them on anything wolf to moose. I have been shooting the 168gr TSX for several years out of my 300 RUM @ 3340fps with devistating results. 2 caribou, 5 black bear, and 4 moose with that load. I also load the 270 TSX in my 375 RUM.
A buddy of mine has used the 120gr TTSX out of a 7mm-08 on moose a couple of times also with great terminal effect. With the 168 TSX I have gotten excellent terminal results as well as accuracy, The last moose I shot first shot thru the back rib quartered thru off shoulder joint, and second shot entered just left of the anus and exited out the front of the chest. Thats 5+ feet of meat, tissue and bone, with obvious expansion.
This year I tried out the 168 TTSX in my 300 RUM. It shot just as well as the TSX with the same loading with just a slight change of POI. I have a custom Remington 700 that has been lightened, and nitrided that I hunt with. Out of its 27" barrel I'm getting 3340fps and accuracy in the .5 MOA range.
I shot a caribou two days ago at 519 yards, first shot center punched the shoulder and exited out behind last rib, second shot high behind the shoulder, I noticed much more damage at the impact sight compared to the TSX bullets in the past which leads me to believe they do in fact expand quicker than the tax, but I also got two exit wounds for both shots, and punched thru a lot of bone so they must hold together also. This was a large bull caribou probably pushing 400 pounds live weight.
This coming weekend we are going to go up and try to get my wife a caribou and I'll let you know how that 130gr TTSX performs on moose or caribou. I would be very surprised if you were not very satisfied with the 130gr TTSX on any whitetail big or small.